As conflict zones go, you could do worse; palm-fringed beaches, fabulous reef diving, and abundant seafood. (It's not often I've had to knock back another lobster.)

It also tops the stakes for exclusive travel destinations. Don't even bother trying to book a tour. You have to persuade one of Asia's defence forces to take you, and it took me almost 20 years of trying.

So it's a great place to go to impress hardcore travellers. The downside is you're unlikely to see anything resembling a toilet or shower.

You'll also run the risk of being sprayed with water cannon by coast guard ships, or rammed onto a coral reef and drowning.

You may not have heard of the Spratly Islands, but if there's another war in our region it's very likely to be where it starts.

Countries have embarked on a program of building in order to try bolster their territorial claims to the islands.

Five nations - Vietnam, Taiwan, Malaysia, Brunei and the Philippines - are competing for sovereignty over parts of the island chain and they're not afraid of using gunboat diplomacy to defend their claims.

But the big kid on the block is China, which asserts ownership of the entire island chain - in fact, the whole South China Sea - and is ramping up efforts to expel what it claims are foreign invaders.

Chinese vessels are currently blockading a Filipino military ship scuttled on an underwater reef, in a bid to starve out a hapless band of marines.

Like most big power conflicts, it is not about defending civilians or enforcing international law. It's mainly about oil.

The Spratly Islands are thought to sit on a vast, untapped undersea oil field, and whoever controls the islands, reefs and sandbars is going to be in the strongest position to exploit it.

Eugenio Bito-onon, known to everyone as Jun, is the mayor of the islands the Philippines has claimed in the Spratlys since the 1950s.

His municipality has just 150 residents, living mainly in a village on the island of Pagasa.

The other inhabitants are small bands of marines and soldiers living rough on tiny patches of rock, reef and sand so China can't occupy them.

He hopes his impoverished country is going to be the winner.

"We call our island group the submerged Saudi Arabia of the Philippines", he told me.

Cramped boat makes three-day trip only twice a year

After many years trying and failing to get to the Spratlys, we persuaded Mayor Jun to take us to Pagasa on a council boat he uses for twice-yearly supply runs.

It was crammed with chickens, pigs, rice, machinery, water, fuel, plants, medicine and nearly 200 passengers - a mix of council workers and island residents returning after a break on the mainland.

The boat was the size of a small ferry, meaning everyone had to sleep side by side.

A lucky few strung hammocks on the upper deck and enjoyed a slight breeze.

The rest of us crammed into the lower deck for three nights of sauna-like heat and rancid smells.

Even the communal-living Filipinos seemed as desperate to get off the boat as the personal-space obsessed Australians.

Mayor Jun is a rarity among Filipino politicians in that he's not doing the job for the money. That's just as well, because the national government gives his municipality hardly any.

Pagasa might be the Philippine's main tool to claim oil riches but it's little more than a collection of huts on dirt tracks.

There's not even a jetty, so we had to wade onto the beach carrying all our supplies.

'There's supposed to be a jetty but they never finished it,' Mayor Jun said.

It seems the money may have disappeared into the pockets of officials in Manila.

Vietnam, China, Malaysia have eyes on the prize

Explore the conflicting territorial claims in the South China Sea

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Rich in resources and traversed by a quarter of global shipping, the South China Sea is the stage for several territorial disputes that threaten to escalate tensions in the region.

At the heart of these disputes are a series of barren islands in two groups - the Spratly Islands, off the coast of the Philippines, and the Paracel Islands, off the coasts of Vietnam and China.

Both chains are essentially uninhabitable, but are claimed by no fewer than seven countries, eager to gain control of the vast oil and gas fields below them, as well as some of the region's best fishing grounds.

Indonesia, Malaysia and Brunei have made claims to part of the Spratlys based on the internationally recognised Exclusive Economic Zone (EEZ), which extends 200 hundred nautical miles from a country's coastline.

Based on the EEZ, the Philippines has the strongest claim on the Spratlys and their resources, with its EEZ covering much of the area.

However the lure of resources, and prospect of exerting greater control over shipping in the region, means that greater powers are contesting the Philippines' claims.

China has made extensive sovereignty claims on both the Spratlys and the Paracels to the north, based largely on historic claims outlined in a map from the middle part of the 20th Century known as the 'Nine Dash Map'.

Taiwan also makes claims based on the same map, as it was created by the nationalist Kuomintang government, which fled to Taiwan after the communists seized power in China.

Vietnam also claims the Spratlys and the Paracels as sovereign territory, extending Vietnam's EEZ across much of the region and bringing it into direct conflict with China.

There have been deadly protests in Vietnam over China's decision to build an oil rig off the Paracels.

One Chinese worker in Vietnam was killed and a dozen injured in riots targeting Chinese and Taiwanese owned factories, prompting 3,000 Chinese nationals to flee the country.

EEZ can only be imposed based on boundaries of inhabitable land, and this has prompted all the countries making claims on the region to station personnel, and in some cases build military bases out of the water, to bolster their claim.

Building and protecting these structures has resulted in a series of stand-offs between countries in the region, each with the potential to escalate.

China has been leading the charge with these installations, and has deployed vessels to the region to protect their interests.

Chinese coast guard vessels have used a water cannon on Vietnamese vessels, as well as blockading an island where the Philippines has deployed military personnel.

Rival claimants have been keener to invest in their holdings.

Vietnam and China have built multi-storey military bases, not just on their islands but on underwater reefs.

Malaysia has even set up a luxury diving resort next to a military base on its island.

(It's the one easy way to get bragging rights to visiting a Spratly island. You can book a diving holiday online.)

China is building up a permanent maritime presence of Coast Guard ships and navy frigates to support its heavily armed bases.

Poor Pagasa has to rely on a dirt airstrip for military flights that can't even land if it rains.

Blockaded marines stuck on rusting hulk

For us, Mayor Jun's island was just a stopping point. Our main destination was a remote reef 14 hours' sailing away, called Ayungin Shoal.

It's where a group of Filipino marines on a rusting, scuttled ship called the Sierra Madre have been blockaded by Chinese maritime forces that want to seize the reef.

The Chinese are determined to stop anyone going there.

In recent months, China has been taking an increasingly hard line against "intruders" in the South China Sea.

In March, it twice blocked a Filipino marine detachment trying to reach Ayungin Shoal, and in April it tried to force back a civilian attempt to bring supplies.

On May 7 a Chinese ship rammed a Vietnamese ship in the disputed Paracel Islands, just north of the Spratlys, before installing a billion-dollar oil rig.